
[Sponsors] 
March 23, 2007, 07:06 
Hi Rafal,
As you said to me

#1 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
Hi Rafal,
As you said to me it was possible, I create my own equation in Foam. In icoFoam.C, I moved the NavierStokes equation for a another eqution easier: nu*Laplacien(U)=Grad(p) In th eicoFoam.C, I wrote this line below: ******************************************** fvVectorMatrix UEqn ( fvm::laplacian(nu, U) ); solve(UEqn == fvc::grad(p)); ********************************************** And I changed anything else, in any files (of course, I made the ./Allmake) But I had a wrong solution, when did: icoFoam SFOAM_RUN/tutorials/icoFoam MyCavity (MyCavity is a case that I created, diferent from the "cavity" case). My solution is actually: ************************************************ Time = 0.01 Mean and max Courant Numbers = nan nan ICCG: Solving for Ux: solution singularity ICCG: Solving for Uy: solution singularity ICCG: Solving for Uz: solution singularity ICCG: Solving for p: solution singularity time step continuity errors : sum local = nan, global = nan, cumulative = nan ICCG: Solving for p: solution singularity time step continuity errors : sum local = nan, global = nan, cumulative = nan ExecutionTime = 0.75 s ClockTime = 1 s ************************************************ I know there is somethin wrong with the timeStep here. But I do not know what and where I have to cahnge things to solve my problem! Can you, or someboby else, give me some advice? Thanks in advance, Lam 

March 23, 2007, 07:36 
Hi Lam,
there can be many c

#2 
Member
rafal zietara
Join Date: Mar 2009
Location: Manchester, UK
Posts: 60
Rep Power: 8 
Hi Lam,
there can be many causes of solution singularity. Several thing that I can see here.  you removed time derivative and you try to solve something in time(maybe start with different solver for steady state ie simpleFoam)  the equation now is diagonally equal (since diffusion term produce diagonally equal matrix; grad(p) is source term) and matrix has to be diagonally dominant to solve it. these are my quick ideas (i can be wrong) rafal 

March 23, 2007, 08:30 
Thamks Rafal to reply me,
I

#3 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
Thamks Rafal to reply me,
I'm thinkin about your ideas. Regards, Lam 

March 28, 2007, 06:04 
Hi world!
I did a big mista

#4 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
Hi world!
I did a big mistake, I delete by accident my doc/Doxygen/html!! How can I get it again??? Thanks in advance, Lam 

March 28, 2007, 06:21 
you can untar OF project in OT

#5 
Member
rafal zietara
Join Date: Mar 2009
Location: Manchester, UK
Posts: 60
Rep Power: 8 
you can untar OF project in OTHER directory
than ~/OpenFOAM. and than move it to right place: i.e: $ mkdir other $ cd other $ tar xzf /path/to/OpenFoam1.3.General.tgz #not sure of name here $ mv other/OpenFOAM1.3/doc/Doxygen ~/OpenFOAM/OpenFOAM1.3/doc $ cd .. $ rm rf other this should work rafal 

March 28, 2007, 09:35 
Oki, Rafal!
You're right!

#6 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
Oki, Rafal!
You're right! Thanks a lot! Lam 

March 29, 2007, 07:30 
Hi world,
I'm wondering mys

#7 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
Hi world,
I'm wondering myself again about simpleFoam.C I noticed that I could put the turbulence in "off": but what kind of equation will I solve as result? Somebody can help me? Thanks in advance, Lam 

March 30, 2007, 03:37 
HEY, everyone!
Nobody can g

#8 
Member
HoangLam
Join Date: Mar 2009
Location: Lausanne, Switzerland
Posts: 60
Rep Power: 8 
HEY, everyone!
Nobody can give me some advice? Cheers, LAm 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
How to solve equation ∂^2U/∂X^2 +∂^2U/∂Y^2  V.Gnanaraj  Main CFD Forum  3  May 31, 2008 14:08 
Can someone tell me how to solve this equation!  Guangli  Main CFD Forum  2  March 29, 2006 00:51 
how can solve this equation  Jianfeng Xia  Main CFD Forum  9  April 10, 2005 19:26 
how to solve an equation at an interface  sreenivas  CFX  0  May 14, 2004 09:35 
How to solve Poisson equation in CFX 4?  windhair  CFX  3  January 27, 2004 22:09 